1. Technical Field
The present invention relates to an electro-optical device in which optical characteristics change according to electrical operations, an electronic apparatus and a method of manufacturing the same.
2. Related Art
An organic Electro Luminescent (EL) panel is an exemplary electro-optical device. In an organic EL panel, a plurality of organic EL elements serving as light-emitting elements having optical characteristics which change according to the magnitude of electric energy is arranged on a substrate. The organic EL panel is generally used as an optical head or an image display device.
FIGS. 8 to 10 show a structure of part of a known EL panel C. FIG. 8 is a plan view, FIG. 9 is a sectional view taken along line Z2-Z2′ in the organic EL panel C shown in FIG. 8, and FIG. 10 is a perspective sectional view illustrating a portion N of the organic EL panel C.
To form light-emitting elements in the organic EL panel C, a hole injection layer and a light-emitting layer (organic semiconductor layer) are sequentially stacked in the apertures Q. The hole injection layer is made of a water-based solution but the light-emitting layer is made of an organic solution. For this reason, the material solution for the hole injection layer permeates into the inner circumferential surface of the first layer 220 and the material solution for the light-emitting layer permeates into the inner circumferential surface of the second layer 230. Subsequently, an electrode is formed on the light-emitting layer. This electrode is shared by all of the light-emitting elements. The light-emitting elements formed through the above-mentioned processes are sealed by a sealing layer. JP-A-2002-372921 discloses a structure of a known organic EL panel C which is almost the same as that described above.
However, the second layer 230 having a lyophobic property is made of an organic material such as acryl, polyimide or the like. Accordingly, the second layer 230 is apt to absorb moisture. For example, when the organic EL panel is manufactured, moisture can easily collect on the second layer 230 and stays on the surface of the second layer 230. The second layer 230 overlaps the pixel electrodes 210 and regions of the substrate 200 in which the pixel electrodes 210 are not disposed. That is, of the lower surface of the electrode provided on the light-emitting layer, a large area is in contact with the surface of the second layer 230. Accordingly, the organic EL panel C has a problem in that the electrode disposed on the light-emitting layer is easily oxidized.
Further, part of the second layer 230 is not covered by the electrode disposed on the light-emitting layer. Accordingly, when the sealing layer is formed by a film formation method using an inorganic material (thin film sealing), part of the sealing layer comes in contact with the second layer 230. In the contact region, the moisture on the surface of the second layer 230 prevents an inorganic material film from being formed. That is, a material for forming the second layer 230 (for example, acryl) is altered by hydration and thus expands in volume, so that the brittle sealing layer breaks. Accordingly, it is difficult to form the sealing layer on the organic EL panel C by the film formation method.